Red clay/mudstone distribution, properties and loess–mudstone landslides in the Loess Plateau, China

Red clay (RC)/mudstone is widely distributed on the Loess Plateau (LP) in China. As a sliding-prone stratum, it controls the formation of loess–mudstone landslides together with active faults. This paper examines the distribution of RC/mudstone and active faults, especially seismogenic faults, and explains their relationship with the distribution of landslides in groups and belts and the difference in landslide scales. Additionally, the paper investigates the scale and mobility of the seismic landslides. All the data of the strata, landslides, active faults, and geotechnical properties come from published documents and geological field investigations. The results reveal that (1) differences in the neotectonic activity and the distribution and outcrops of RC/mudstone affect the landslide type and scale; (2) the landslides are mainly densely distributed along rivers and fault zones and are characterized by an obvious scale difference along a river; and (3) the landslides triggered by seismogenic fault activity and earthquake activity are mainly concentrated in the Neogene mudstone basin to the west of the Liupan mountain range. The abundant data provide a reference and foundation for the engineering geologist and lay a scientific foundation for subsequent investigation, hazard zonation, prediction and forecasting, regional prevention, and control of landslide disasters on the LP.